CAIE S2 2023 November — Question 7

Exam BoardCAIE
ModuleS2 (Statistics 2)
Year2023
SessionNovember
TopicPoisson Distribution
TypeSingle time period probability

7 A random variable \(X\) has the distribution \(\operatorname { Po } ( 2.4 )\).
  1. Find \(\mathrm { P } ( 2 \leqslant X < 4 )\).
  2. Two independent values of \(X\) are chosen. Find the probability that both of these values are greater than 1 .
  3. It is given that \(\mathrm { P } ( X = r ) < \mathrm { P } ( X = r + 1 )\).
    1. Find the set of possible values of \(r\).
    2. Hence find the value of \(r\) for which \(\mathrm { P } ( X = r )\) is greatest.
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